Commutator-truer



(No Model.)

D.A MOGENNSS. GOMMUTATOR TRUER.

Patented Mar. 17,1891.

/fv VEA/ro@ A WOR/VDS Urirrnn Sterns (c ritter.

DAVID MCGENNISS, Ol" AMSTERDAM, XEY YORK.

COMMUTATORMTRUER.

SPECFICATION forming part of Letters Patent No. 448,540, dated Mai-cli 17', 1891.

Application tiled June l0, 1890. Serial No. 354,985. (No model.)

lniproved Coiniiiutatoi-'l`riier, of wh ich the folg lowing is a specifica-tion, reference being had tothe an n cned drawings, vtorniing a part thereol", in Which- Figure l is a perspective view showing the application of iny improved eoinin utator-truer is a transverse section i to a dynanio. Fig. 2 taken through one of the supports of the truing-instrunient, and Fig. 3 is an inverted plan i view of the truing-iiistruinent.

Similar letters of reference indicate corresponding parts in all the views.

The object of iny invention is to provide a siinple and effective device for truing the coininiitators et dynamo-electric machines and inotors after they have been Worn by the friction of the brushes and by the action ot the current.

.My invention consists in a pair of adjustable guides fitted to the brush-holdin g arin of a coininutator, a sliding rod iitted to the guides, and a plate carried bythe sliding rod and Vtui'- nislied with an abrading or ciittin g surface, all as will be hereinafter more fully described.

The coin in utator-eylinderA, ivhichis in cunted on the armature-shaft B and connected with the conductor et the arniatiire C, is constructed and arranged in the usual way.

Upon the journal-box D of the armature shaft E is adjustably inounted the brush-holding arni E, provided at its extremities With apertures a tor receiving the brush-holding rods.

ln applyinfi' niy iinproveinent to a dyiiaino the brushes and brush-holding rods are renioved and in their places are inserted rods F F. To these rods are fitted the supports G G', consisting of the sleeves Zi b", titted to the rods F F" and clainped by set-screws c c and right-angled arnis d d', extending laterally from the sleeves ti h in opposite directions, as shown. The upright portion ot the arin d is bored to receive the shank c of the fori; H, the said shank being clamped in the arni d by the set-screw ff ln the fork H is pivoted a sleeve l upon the ends of the screivs g, which i pass through the arnis of the said forli. ln a plain bore in the upright portion of the arni d is inserted a screw-threaded rod e', to which is fitted a nut e?, bearing upon the top of the arin. The upper end ot the rod c is provided with a fork ll, in which is iivoted a sleeve l on the ends ot the screws g. ln the sleeves l l is inserted a rod J, provided at one end with a handle li for convenience in inanipulatine* the truer. The iortion of the rod J passing through the sleeve l is grooved lon- 3 gitudinally, and iii the said sleeve l is inserted a screvv 7i, which projects into the groove of thc rod J and prevents the rod 'frein turning, To the rod J is iitted the apertured ear if of the plate L, and the ear is furnished with a set-screw f', by means of .which the plate liinay be clamped in any desired position along the length of the rod or at any desired angle with reference to the axis of the coinin utatorcylinder A. To the under surface oi. the plate L is clainped a plate M of abrading inatei'ial or a plate to which abrasive inaterial has been applied.

ln practice l' provide eincry-blocks of different grades tor reducing the surface of the coin niutator-cylinder to plain cylin drieal forni. l also provide plates furnished with elastic or seinielastic pads coated with ein ery or other abrasive or polishing inaterial for smoothing and iinishing the coininutator-cylinder after it has been reduced to proper'foiin. The plate L Ais raised or lowered by turning the nut ci in one direction or the other, and it is moved backward and forward across the coniinutatorcylinder as the cylinder revolves and is grad ually lovvered by turning the nut c2 until the coin in utator is inade true and provided With a suitable finish for again receiving the conin'iutator-brusheslf the coiiiiniitatoicylinder is Worn conically, the plate L iiiay be inclined at a suitable angle and the coiiiiiiiitatoi'eylinder inay be inade perfectly round without the necessity et reducing it to a cylindrical forni.

Having thus described niy invention, l cla-iin as ncvv and desii'e to securev by Letters Patentm l. A truing attachment for dynainos, coinprising txvo supports having attaching-rods IOO to enter the brush-rod, apertures at opposite ends of the brush-holding arm, vertical posts mounted in said arms and carrying` aligned sleeves, and a rod passed through said sleeves and having an abrader between its ends to engage the surface of said cylinder, substantially as described.

2. A truing attachment for dynamos, comprising supports adapted for connection with the opposite ends of the brush-carrying arm,

. vertically-adjustable posts carried by said supports, vertically-rocking aligned sleevesl l mounted on said posts, and a rod ext-ending through both sleeves and provided with an abrading device between its ends, substantially as described.

3. ln a commutator-truer, the combination ot' a support adapted for attachment to the brush-supporting arm, a rod movable lengthwisc in the support, and an adjustable abrad arm E and the co1nmutator-cylinder A of a dynamo, of au abrading-plate L, and supports fitted to the arm E at opposite sides ot said cylinder and adapted to hold the plate'in the position of use, substantially as specified.

DAVID MCGENNISS.

Witnesses:

W. M. BARTLETT, JOHN P. GOING. 

